Sound recording and reproducing instrument.



G. KIRKEGAARD. SOUND RECORDING AND BBPBODUGING INSTRUMENT. 'APPLIdATIOI Hum xov.1s, 1899. BEIEWYED n3. 5, 1908.

900,392, Patentgd Oct. 6, 1908.

llllmllllll lilllllllllll pmrni sfrnl ns PATENT OFFICE.

GEO RG KIRKEGAARD, OF NEW YORK, N. Y., ASSIGNOR TO STILSON I'IUTCHINS, OF

WASHINGTON, DISTRICT OF COLUMBIA.

SOUND RECORDING AND REPRODUCING INSTRUMENT.

Application filed November 18, 1899,

Specification of Letters Patent.

Patented Oct. e, 1908.

Serial No. 737,406. Renewed March 5, 1908. Serial No. 419,391.

To all whom it may concern:

Be it known that I, GEORG KIRKEGAARD, a citizen of the United States, and resident of the city of New York, in the borough of Brooklyn and State of New York, have invented a certain new and useful Sound Recording and Reproducing Instrument, of which the following is a specification.

This invention relates to phonographs, the primary object being to provide a method of .recording, and reproducing from a record,

speech, without the necessity of making me- 0 anical impressions upon a recording surface, as is the common practice.

It is well known that man of the foreign sounds and noises heard in t e reproduction of s eech from an ordinary wax record of a p onograph is due to the fact that the stylus or the diaphragm travels in me chanical contact with the record, and the rubbing of the oint upon the record is responsible, in a arge measure, for these dis turbing sounds.

The ordinary phonograph is a mechanical device in so far as its recording and reproducing elements are concerned. My invention comprehends the recording and reproducing of speech through the agency of electro-magnet1sm, the record being produced by varying the magnetic condition of a series of magnets capable of retaining such magnetic condition for an indefinite period, then causing such magnets to successively act upon a reproducing diaphragm ordevice. I produce this varied magnetic con-' dition of the magnets without mechanical contact between relatively moving parts, in consequence of which the reproducer is affected by only such influences as were produced by the recorded speech. Since my invention is o erated electrically, the principle involve may be applied in telephony, telegraphy and electric signaling of any character. For this purpose speech or sounds to be recorded may be delivered into a telephonictransmitter and sent over a line of any length, by any known methods,and at in the line may pass through the phonographic apparatus constituting my invention and make a record which may be reproduced at any time and in any manner.

To explain my invention in detail I will reany point or points ,tional form and in accordance with one of the plans by which the princi le may be 'carried out; Fig. 2 shows a slig 1t modification of the electrical apparatus and circuits; Fig. 3 shows a further modification of such apparatus and circuits; Fig. 4 is a trasverse section of a cylindrical record medium constructed on a modilicd plan; Fig. 5 shows in side elevation still another modification of the record; Fig. 6 illustrates the reproducer, and Fig. 7 shows the use of my invention as a telephonic relay.

In'accordance with my invention the record or record medium,which is the device to be affected by the speech and in turn affects the reproducing mechanism, consists of a surface presenting, or made up of, individual or insulated particles or pieces of material, such as hardened steel, which is capable of being magnetized and retaining its magnetism for an indefinite period. This surface, which maybe in the form of a cylinder, disk or other shape, may have its particles of steel disposed thereon in any sultable way. As shown in Fig. 1 for instance, the cylinder A is made of wax, rubber, celluloid, shellac or similar adhesive insulating material acting as a base or binder to contain hardened steel filings, the amount of filin s being refei'ably as much as the base Wlll hold, t 1e exposed outer surface being made as true and smooth as possible. Or, the ocment base may hold within or upon it a quantity of small steel pins which may project radially from the base with their ends presented over the entire surface of the record, or such steel pins may be in a horizontal or other position. The record may also be made up of bits of hardened steel wire bent into the shape of the letter U and secured at the bend in a textile or other backing, which is wrapped around the record cylinder or secured to a frame of any character adapted to carry the record. These bent wires all over the surface of the backing will present the appearance of a brush, each wire acting as a magnet in the carrying out of my invention. Likewise, short lengths of ribbon steel or steel plates may be attached to a moving surface and magnetically insulated from each other to receive the magnetic impressions.

The means for producing the recording medium or ma etic impressions upon'the record medium y s eech consists of a magnetic core I), a pole E of which is presented to the surface containing the steel particles or pieces described, there being suflicient clearance left between the face or end of the pole and the surface of the record, to permit of relative motion of these two parts without mechanical contact. This magnetic core is surrounded by a coil of wire 0 through which variable or undulating currents are caused to flow, which currents are created or induced by and in accordance with the sound waves which are to be recorded and reproduced.

As shown in Fig. 1, the coil 0 is in a circuit 12 containing a battery B and a telephonic transmitter T of any approved type. The sound waves which enter the transmitter create corresponding changes in the resistance of the circuit and so produce corresponding changes of magnetism in the core I).

In Fig. 2 the transmitter is in circuit with the primary of induction coil I, the secondary of which extends to, and includes, the coil 0 on the magnetic core. For long distance transmission this will be preferable to the form shownin Fig. 1. If desired the circuit containing the primary of'the induction coil and transmitter may also include a second coil 0 on the core I) which, if properly wound, will augment the influence of the coil 0, (see Fig. 3.)

The mechanical appliances necessary for this apparatus may consist of a suitable motor which for brevity I have indicated by the ear wheel G, for revolving the record surace in front of the pole I) of the magnet, and suitable means for moving the magnet across the face of the record so that new portions of it may be constantly presented to the pole while the machine is in operation. For this purpose a worm shaft S passing through a nut n attached to the core I) or its frame, is rotated by the gear 9, but any suitable mechanism may be substituted for these devices.

The operation of producing the magnetic record is as follows: Sounds which enter the telephonic transmitter T Will create corresponding variations of current in the circuit which it controls, which variations will either be delivered direct to the coil 0 or first through the induction coil I and then to the coil 0. These variations will create corresponding variations in the ma netic strength of the core I), and the lines 0 force passing through its pole piece I) and through the steel particles or pieces in the recording surface will transform such particles or pieces into magnets the magnetism of which will be hardened steel.

retained for an indefinite period on account of the fact that the particles are made of Assuming the recording surface and the magnet to have the relative motions above described, it is evident that the magnetism of the successive individual magnets in the recording surface which pass in front of the pole of the magnet will be of greater or less strength in exact proportion to magnetic surface of the cylinder.

the strength of the magnet core b when the particles pass under its influence. The result of this upon the record will be the pro duction of a spiral line or row of little magnets extending from one end of the cylinder towards the other. I prefer to make the pole b of the magnet pointed, as shown, so that the row of magnets 9 produced by it will be narrow and therefore enable me to put a large number of the spiral rows upon the cylinder.

In order to increase the magnetic effect of the magnet b I may mount the record cylinder A u on'a soft iron drum or cylinder D. This will decrease the resistance of the magnetic circuit and enable meto move the individualmagnets in the record surface through a very narrow fair gap or field of force between two magnetic bodies. If the record is in the form of a disk, an iron backing may also be used.

A record thus produced may be used at any time thereafter in the following manner: The core I) with its coil is removed from the machine and the reproducer shown in Fig. 6 substituted. This reproducer consists of a diaphragm d to the center of which is fixed an armature d of soft iron having a pointed end similar to the point I) of the magnet. When the reproducer is adjusted in place of the magnet, the oint of the armature occupies the same re ative position with respect to the surface of the record as did the point b Opposite the other side of the diaphragm of the re )roducer may be attached a megaphone or ot er device for increasing the sound waves created by the diaphragm. When the same motions'are imparted to the record cylinder and reproducer, given to the cylinder and magnet, as were before, the little magnets in the surface of the record, as they successively pass the armature (1, will attract it "more or less, depending upon the strength of magnetism in each instance, and the diaphragm will therefore vibrate and reproduce upon the air the sound waves that were originally delivered to the transmitter.

I do not limit myself in any manner to the size or shape of the individual metallic particles in the surface of the record. As one of the objects of my invention is to avoid mechanical contact between the moving parts it will be understood that in this respect my inventionis not limited to the nature of the It may also be remarked that in the production of the record mechanical contact between the magnet core I) and the recording surface would not tend to make a poor record, but quite the reverse. But in reproducing, the contact is not desirable. Hence I may arrange to let the end or pole of the magnet b slide upon the record surface in making the record and the armature of the reproducer run clear in reproducing the sounds. It will also be understood that the diaphra m of the reproducer may be used as the diap ragm of a micro hone transmitter wherein its vibrations wi l vary the resistance of a circuit containing any preferred form of receiving apparatus;

The magnetic condition of the record may be nullified at any time and the surface used for a new record, by using any known means of demagnetizing.

This invention will serve admirably as a telephonic relay or repeater and as such the reproducing or repeating may be done after 'diately after they the message has been recorded as before described, or, simultaneously with the production of the record. Accordin to the latter plan a microphone r may be p aced immediately' behind the recording magnet b and move with it, and thus receive and transmit the impulses of the magnetized bodies immehave been magnetized b the magnet b, as illustrated in Fig. 7.

Having described my invention, I claim 1. A sound recording and reproducing instrument consisting of a number of magnetizable bodies arranged in a series, means for successively magnetizing said bodies in accordance with sound waves and a diaphragm subjected to the successive action of said bodies.

2. A sound recording instrument consisting of an electro-magnet and means for varying its magnetism in accordance with sound waves, in combination with a relatively moving surface containing a multiplicity of pieces of magnetic material adapted to be successively brought under the influence of the magnet.

3. A sound recording and reproducing instrument consisting of a series of independ ent bodies of magnetizable material, means for successively magnetizing them in accordance with successive changes in sound waves and an armature adapted to be brought successively under the influence of said bodies after they have been magnetized.

4. The combination of a'nelectric circuit,

a magnet in said circuit, a series of magnetizable bodies adapted to be magnetized successively under the influence of said magnet, and a record electric circuit adapted to be affected successively by the said magnetized bodies.

5. A sound recording and reproducing instrument consisting of an electro-magnet and means for changing its strength in accordance with sound waves, and a relatively moving surface of magnetic material exposed to the influence of said magnet for the purpose of making a record of said sound waves, in combination with a reproducing device consisting of a vibratory body carrying an armatureadapted to be exposed to the magnetic record contained in said moving surface, substantially as described.

6'. In "a telephonogr h, the combination with a magnetic record medium having a multiplicity of record portions partially insulated from one another, of a recording medium 006 erative therewith.

'7. In a te ephonogra h, the combination with a magnetic recor medium having a multiplicity of record portions partiallyinsulated from one another lengthwise and crosswise of the line of record, of a recording medium cooperative therewith.

8. In a telephonogra h, the combination with a magnetic recor medium having a multiplicity of record ortions partiallyinsulated from one anot er lengthwise, crosswise and depthwise of the line of record, of a recording medium cooperative therewith. 9.. In atelephonograph, the combination with a magnetic record. medium having a plurality of record portions dis osed depthwise of the medium and partia ly insulated from one another, of a recording medium cooperative therewith.

10. In a tele hono raph, the combination with a relative y thic magnetic record medium havin a multiplicity of record ortions partial y insulated from one anot er, of a recording medium for impressing into depth.

11. In a tele hono aph, the combination with a relative y thic magnetic record medium having a multiplicity of record portions partially insulated from one another, of means for im ressing into said record medium a line oi partially insulated magnetic records each extending entirely through said medium.

12. Ina tele hono aph, the combination with a relative y thic magnetic record medium having a multiplicity of record ortions partia y insulated from one anot er, of means for impressing into said record medium a line of partially insulated needle-like magnetic records each extending entirely through said medium.

13'." In a telephonogra h, the combination with a magnet1c record 5 plicity of record portions partially insulated rom one another, of a recording medium for impressing into said record disk a line of partially. insulated magnetic records.

14. In a device of the characterdescribed, the combinationof a magnet and a magnetic record medium adapted to be influ-' enced by and to influence said magnet, means for supporting said record medium and said ma net in such ositions that the pole of sai ma net is a jacent to but out of contact wit said record medium, and means for producing-relative movement of sai magnet and record medium.

isk having a multi-' 15. In a device of the character described,

the combination of a record medium of substantial width, a magnet adapted to influence and be influenced by said record medium and means for imparting relative movement to said record medium and magnet to cause the magnet to trace a diagonal or spiral line with respect to the surface of the medium".

16. In a device of the character described, the combination of a record medium, a magnet adapted to influence or be influenced by said medium, a telephonic transmitter comprising an induction coil having rimary and secondary windings, and two coi s applied to said magnet, one of said coils being in circuit with the primary of the induction coil, and the other coil being in circuit with the 'secondary of the said induction coil.

17. In a device of the character described, the combination of a magnet and a record medium adapted to influence and be influenced by said magnet, said record mediuni being magnetically discontinuous.

18. In a device of the character described, the combination of a magnet and a record medium adapted to influence and be infiuenced b said magnet, said record medium being p iysically continuous and magnetically discontinuous.

19. In a device of the character described, the combination of a magnet and a record= medium adapted to influence and be influenced by said magnet, said record medium being composed of a suitable base or binder and magnetic particles held thereb 20. In a device of the character escribed, the combination of a magnet and arecord medium adapted to influence and be influenced by said magnet, said record medium being composed of a suitable base or binder and steel filings held thereby.

Signed at the city of New York in the county of New York and State of New York this 16th day of November A. D. 1899.

GEORG KIRKEGAARD. Witnesses WM. BAHT, LUDWIG Omns'rnn, Jr/ 

